51 research outputs found
Registration of the First Thermonuclear X-ray Burst from AX J1754.2-2754
During the analysis of the INTEGRAL observatory archival data we found a
powerful X-ray burst, registered by JEM-X and IBIS/ISGRI telescopes on April
16, 2005 from a weak and poorly known source AX J1754.2-2754. Analysis of the
burst profiles and spectrum shows, that it was a type I burst, which result
from thermonuclear explosion on the surface of nutron star. It means that we
can consider AX J1754.2-2754 as an X-ray burster. Certain features of burst
profile at its initial stage witness of a radiation presure driven strong
expansion and a corresponding cooling of the nutron star photosphere. Assuming,
that the luminosity of the source at this phase was close to the Eddington
limit, we estimated the distance to the burst source d=6.6+/-0.3 kpc (for
hidrogen atmosphere of the neutron star) and d=9.2+/-0.4 kpc (for helium
atmosphere).Comment: 12 pages, 6 figure
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Noble gases from the interstellar medium trapped on the MIR space station and analyzed by in vacuo etching
Introduction: The composition of the present interstellar medium (ISM) provides an important benchmark in cosmochemistry. It serves as a reference for galactic chemical evolution (GCE) models, solar mixing predictions and provides information for understanding Big Bang nucleosynthesis. The present-day ISM 3He abundance allows, combined with the protosolar 3He, deduced from the Jovian atmosphere or meteorites [1,2], tracing the GCE over the past 4.56 Ga. 3He/4He = (2.5 0.6) x 10-4 has been determined for the local ISM [3]. However, the uncertainty is too large to better constrain GCE models and - in combination with the present-day solar wind value - the protosolar D/H [4]
Nucleon-induced fission cross-sections of tantalum and separated tungsten isotopes and "compound nucleus" effect in intermediate energy region
Neutron- and proton-induced fission cross-sections of separated isotopes of
tungsten (182W, 183W, 184W, and 186W) and 181Ta relative to 209Bi have been
measured in the incident nucleon energy region 50 - 200 MeV using fission
chambers based on thin-film breakdown counters (TFBC) using quasi-monoenergetic
neutrons from the 7Li(p,n) reaction and at the proton beams of The Svedberg
Laboratory (TSL), Uppsala University (Uppsala, Sweden). The results are
compared with predictions by the CEM03.01 event generator, as well as with the
recent data for nuclei in the lead-bismuth region. The effect of "compound
nucleus" in the intermediate energy region is discussed, displaying in
exponential dependence of nucleon-induced fission cross-sections on the
parameter Z^2/A of the composite system (projectile+target nucleus), and in
other characteristics of the fission process for which parameter Z^2/A plays a
role similar to the one of the usual liquid-drop parameter Z^2/A of compound
nuclei.Comment: 4 pages, 3 figures, 2 tables, only pdf file, to be published in Proc.
Int. Conf. on Nucl. Data for Sci. and Technology (ND2007), Nice, France,
April 22-27, 200
New fast X-ray transient IGR J18462-0223 discovered by the INTEGRAL observatory
Details of the discovery of a new X-ray source, IGR J18462-0223, on October
12, 2007, during a short (several hours), intense (~ 35 mCrab at the peak)
outburst of hard radiation by the IBIS/ISGRI gamma-ray telescope onboard the
INTEGRAL observatory are given. The detection of another earlier outburst from
this source occurred on April 28, 2006, in the archival data of the telescope
is reported. We present the results of the source's localization and our
spectral/timing analysis of the observational data. The source may turn out to
be yet another representative of the continuously growing population of fast
X-ray transients, which are the focus of attention because of the
identification of their optical counterparts with early-type supergiants
CEM03 and LAQGSM03 - new modeling tools for nuclear applications
An improved version of the Cascade-Exciton Model (CEM) of nuclear reactions
realized in the code CEM2k and the Los Alamos version of the Quark-Gluon String
Model (LAQGSM) have been developed recently at LANL to describe reactions
induced by particles and nuclei for a number of applications. Our CEM2k and
LAQGSM merged with the GEM2 evaporation/fission code by Furihata have
predictive powers comparable to other modern codes and describe many reactions
better than other codes; therefore both our codes can be used as reliable event
generators in transport codes for applications. During the last year, we have
made a significant improvements to the intranuclear cascade parts of CEM2k and
LAQGSM, and have extended LAQGSM to describe photonuclear reactions at energies
to 10 GeV and higher. We have produced in this way improved versions of our
codes, CEM03.01 and LAQGSM03.01. We present a brief description of our codes
and show illustrative results obtained with CEM03.01 and LAQGSM03.01 for
different reactions compared with predictions by other models, as well as
examples of using our codes as modeling tools for nuclear applications.Comment: 12 pages, 10 figures, to be published in Journal of Physics:
Conference Series: Proc. Europhysics Conf. on New Trends in Nuclear Physics
Applications and Technologies (NPDC19), Pavia, Italy, September 5-9, 200
Broadband X-ray spectrum of XTE J1550-564 during 2003 outburst
Results of broadband INTEGRAL and RXTE observations of the Galactic
microquasar XTE J1550-564 during outburst in spring 2003 are presented. During
the outburst the source was found in a canonical low/hard spectral state.Comment: 5 pages, 3 figures. Accepted for publication in Astronomy Letter
Modern aspects of the use of plasma enriched in soluble platelet factors in the treatment of injuries and diseases of the musculoskeletal system
The review of literature presents the new direction in the treatment of sports injuries and diseases of the musculoskeletal system – using of autologous platelet-rich plasma/plasma enriched in soluble platelet factors (PRP/PORFT). PRP/PORFT reveals anti-inflammatory, analgesic, anticatabolic and regenerative effects after local injection to affected area. Technology of preparation and clinical application of PRP/PORFT were under consideration. There were described the results of clinical studies on PRP/PORFT application in sports medicine and damage of musculoskeletal system. It was shown the clinical efficacy of 2-3 injections of PRP/PORFT into the area of muscle, ligaments, joints injury. Most effective use of PRP/PORFT was shown for therapy of lateral epicondylitis and osteoarthritis. There were no yet evidences for its efficacy in therapy of patients with damaged Achilles tendon. The best clinical effects of PRP/PORFT use was demonstrated in patients with trauma and damage of musculoskeletal system at the initial stages of treatment, and also as a part of rehabilitation courses
Detection of large-scale X-ray bubbles in the Milky Way halo
The halo of the Milky Way provides a laboratory to study the properties of
the shocked hot gas that is predicted by models of galaxy formation. There is
observational evidence of energy injection into the halo from past activity in
the nucleus of the Milky Way; however, the origin of this energy (star
formation or supermassive-black-hole activity) is uncertain, and the causal
connection between nuclear structures and large-scale features has not been
established unequivocally. Here we report soft-X-ray-emitting bubbles that
extend approximately 14 kiloparsecs above and below the Galactic centre and
include a structure in the southern sky analogous to the North Polar Spur. The
sharp boundaries of these bubbles trace collisionless and non-radiative shocks,
and corroborate the idea that the bubbles are not a remnant of a local
supernova but part of a vast Galaxy-scale structure closely related to features
seen in gamma-rays. Large energy injections from the Galactic centre are the
most likely cause of both the {\gamma}-ray and X-ray bubbles. The latter have
an estimated energy of around 10 erg, which is sufficient to perturb the
structure, energy content and chemical enrichment of the circumgalactic medium
of the Milky Way.Comment: Author's version. 17 pages, 5 figures, Published in Nature 2020, Vol
58
A Hard X-ray survey of the Galactic Center with INTEGRAL/IBIS. Catalog of sources
During the period Aug.23-Sept.24 2003, the INTEGRAL observatory performed an
ultra deep survey of the Galactic Center region with a record sensitivity at
energies higher than 20 keV. We have analized images of the Galactic Center
region obtained with the ISGRI detector of the IBIS telescope (15-200 keV) and
present here a catalog of detected sources. In total, 60 sources with a flux
higher than 1.5 mCrab have been detected. 44 of them were earlier identified as
Galactic binary systems, 3 are extragalactic objects. 2 new sources are
discovered.Comment: 6 pages, 3 figures. Accepted for publication in Astronomy Letters.
Version with original quality figures can be taken from
http://integral.rssi.ru/~mikej/integral_gc_survey_pazh_eng.ps.g
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